function my_clock(el){
    var today=new Date();
    var h=today.getHours();
    var m=today.getMinutes();
    var s=today.getSeconds();
    m=m>9?m:('0'+m);
    s=s>9?s:('0'+s);
    el.innerHTML=h+':'+m+':'+s;
    setTimeout(function(){my_clock(el)},1000);
}
var clock_div=document.getElementById("clock_div");
my_clock(clock_div);
